nearly crushed my racquets just for the heck of it.

I've got a racquet (2 of em) superb power, and after tweaking the specs a bit, decided against using them for wood in my next bon-fire.

Literally, I could barely even hit the strings.. Everything was shanking off the frame left and right.

So just out of dumb luck, I decided to add 2 Fishing weights at 10 and 2 o'clock. Crushed with pliers and taped up with electric tape.

It turned this racquet into a F'n weapon. I haven't had the opportunity to intimidate opponents with it yet, because we know all of our league opponents... but when I head to state next week, I plan to crush a few net men just for the sheer fun of "if ya gonna play the net, be ready".

At any rate, the added weight has turned my serves and forehands into monsters. My backhand was already a monster for the most part, but the new weight has it to where if the ball isn't in the strike zone, I'm hesitant to hit an aggressive topspin shot. If it's too high, sometimes I can't get enough spin on it to drop it into the court. And even when it is in the strike zone, I need what seems to be a lot more time to prepare and set up... otherwise your guess is as good as mine as to where it'll end up.

I guess I can answer my own question here, but it helps to type it out. What should I do in this situation? I've developed, since adding the weight, a nice slice backhand when I'm hesitant to go for the topspin shot... I'm not even sure how to practice, because it's almost as if every ball i hit -- if it's not right where I need it to be to hit my old backhand -- is unpredictable unless I see and set up super early.

Figure I might need to just hit against a ball machine to try to re-groove this thing. Not sure what else to do.

Sounds like a modification I may want to try. You should try practicing topspin groundstrokes with even more weight hittable applied( about 8 onces hittable weight). After you hit some controlled groundstrokes with the slide on hittable stroke training weight you should be able to maximize the benefit of your racquet weight modification, handle it easier and be able to control it with more confidence and feel due to practicing with the heavier hittable weight. You will regain and maximize your topspin. This is exactly what the PT WinSock is designed to do. Power and topspin training.Check it out. http://www.ptwinsock.com/ProTrainer_WinSock.html

Another adjustment is to move your weights closer to the racquet throat and the center point of balance. Maybe instead of 10 and 2 you could go to 7 and 5 or in the throat at the bottom of the racquet head frame. I think you are closing in on it though.